This invention relates generally to monitoring animate and inanimate objects. More particularly the present invention is a form of electronic leash for animals, an electronic tag for people, and an electronic “tether” for portable objects carried by individuals.
Finding an object requires there be some perception that the object is missing. In the case of valuable objects, the delay in perception may be costly. How many times does a person notice many hours later, that a purse or other object has been left at a store or restaurant? By that time, the object may be out of range of the finding device, either because the owner has left the vicinity of the object or the object has been removed from the vicinity of the owner.
“Electronic tethers” have been proposed using a variety of technology. The most common system uses a monitoring module and an alert module. In this system, the monitoring module comprises a transmitter. The alert module receives a signal from the monitoring module and determines the distance between the alert module and the monitoring module. When a predetermined distance is exceeded, the alert module issues an alarm. Variations of this system add a transmitter in the monitoring module to allow the alert module to poll the monitoring module and to react when the monitoring module fails to respond.
In co-owned U.S. application Ser. No.: 10/911,018, an “electronic tether” is described that uses an RFID tag as the monitoring module. The alert module comprises an RFID polling system. The system issues an alert when an RFID tag fails to respond to a polling signal.
In co-owned U.S. application Ser. No.: 10/832,498, an “electronic tether” is described that uses an audio signal as a polling signal. The monitoring module and the alert module each have a clock that is synchronized to a common time. The distance between the alert module and the monitoring module is determined by the propagation time of an audio signal sent by the monitoring module to the alert module.
What would be truly useful would be a system that comprises an “electronic leash” or “electronic tether” which can be variably preset by an animal owner or object owner and operated so as to prevent the animal, person or object from becoming separated from its owner. Such a system would further be capable of identifying a specific animal, person, or object that is missing from a group of monitored animals or objects. Without meaning any disparagement, this application shall refer to people, animals and objects collectively as objects. Similarly, the term “owner” as used herein is synonymous with owner, parent, caregiver and the like.